Hallow Spell
D&D Hallow Spell Description: Hallow makes a particular site, building, or structure a holy site. This has four major effects.
First, the site or structure is guarded by a magic circle against evil effect.
Second, all Charisma checks made to turn undead gain a +4 sacred bonus, and Charisma checks to command undead take a -4 penalty. Spell resistance does not apply to this effect. (This provision does not apply to the druid version of the spell.)
More on the Dungeons & Dragons Hallow Spell